GB2348669A - Mixed direct fuel injector for i.c.engines - pre-mixes fuel and air before direct injection - may be combined with spark plug - Google Patents

Abstract

A combination Mixed Direct Injector and Spark Plug (Fig 6), comprising a fitting, 1, embodying a communal mixing passage, 2, having a stationary mixing helix, 5, and discharge nozzle outlet aperture, 7, fed by two electronically controlled solenoid operated injectors, 3 and 4, supplied by pressurised fuel, 3p, and pressurised air, 4p, respectively, the fitting, 1, having spark plug components - high tension insulator, 27, high tension terminal, 28n, terminal stud, 28s, spark electrode tip, 28, earth electrode, 26, hexagon nut facets, 29, sealing washer, 30, and mating spark plug screw threads, 8, for direct connection into spark plug holes, 9, of combustion chambers, 10, of an internal combustion engine.

Description

Mixed Direct Injector and Spark Plug FIELD: The present invention relates to a Mixed Direct Injector and Spark Plug for use on most Internal Combustion Engines.

SCOPE OF USES: For improved combustion efficiency, power, and emissions on most internal combustion engines including two-strokes, four-strokes, spark ignition, compression ignition, Wankel, Reciprocating piston, and the latest Satellite Rotating piston engines. More importantly, the MDI Plug-Mixed Direct Injector and Spark Plug -enables the efficient use of diesel fuel in spark ignited gasoline engines.

EXISTING STATE OF THE ART: Since internal combustion engines were developed, engineers and inventors have endeavoured to enhance fuel supply and mixing systems to improve efficiency and power output with minimum exhaust pollution.

Improvements have included the Carburettor, Single Point Injection, Multi Point Injection, and recently Gasoline Direct Injection (GDI). Since 1993 few Carburettors, can meet current minimum exhaust pollution regulations.

PRESENT DAY SHORTCOMINGS: Since all present day fuel injectors inject pure gasoline, mixing takes place after injection inside the combustion chamber, and is dependent upon air flows which vary with engine speed and load conditions. Even GDI engine pistons have curved top shapes. GDI is an expensive option as it requires major modifications in engine design and production, particularly to the cylinder head and pistons. Furthermore, none of the present injectors enable use of diesel fuel in spark ignited gasoline fuel engines.

OBJECT : The object of the present invention is to overcome the above shortcomings.

MDI-Mixed Direct Injector-pressurised supplies forcibly pre-mixes fuel and air before injecting it directly into the combustion chambers, so that effective mixing is independent of air flows, engine speed or load. MDI is not an expensive option, as MDI Plugs can be inserted in the spark plug holes of existing production engines without modification. MDI Plugs enable efficient use of diesel fuel in spark ignited gasoline fuel engines with minimum of modification and expense-a breakthrough. PRIOR ART: A search carried out on the World Patent Index revealed no anticipations of the present invention.

Summary of the Invention : A Mixed Air/Fuel Direct Injector for direct screw connection to the combustion chamber of an internal combustion engine comprising a fitting embodying a communal mixing passage with stationary mixing helix and discharge nozzle fed by two electronically controlled solenoid operated injectors supplied by pressurised fuel, and pressurised air respectively, the enhanced fitting embodying Spark Plug components,-High Tension HT terminal, insulator, conductor stud, electrode tip, and earth electrode.

MDI Operation Sequence of Events triggered bv ECU : a) Inlet port shuts compression stroke begins b) Fuel injector triggered to feed fuel into communal mixing passage c) Air injector triggered to blow air through communal mixing passage d) Air/fuel swirl mixed by helix and conical shaped propeller e) Combustible air/fuel invisible cloud sprayed via nozzle into combustion chamber f) Fuel injector triggered to switch off first, followed by air injector off. g) Ignition triggered followed by expansion, exhaust and intake.

ADVANTAGES: a) MDI is independent of the vagaries of air flows, engine speed or load. b) MDI produces an invisible combustible cloud close to the spark electrodes easily ignited even by a weak spark enhancing combustion efficiency. c) MDI is not an expensive option, as MDI Plugs can be inserted in the spark plug holes of existing production engines without modification. d) MDI is able to supercharge an engine after the inlet port is shut, resulting in increased Compression Ratio and Power Output. e) MDI Plugs serve the triple role of mixing, direct injection and ignition. f) MDI Plugs enable efficient use of diesel fuel in spark ignited gasoline fuel engines with minimum of modification and expense-a Breakthrough.

REFERENCE TO DRAWINGS: FIG. 1 illustrates a typical first embodiment of the invention showing a sectional view of the fitting and the pressurised supplies, with fuel and air injectors not sectioned.

FIG. 2 is a typical electrical circuit diagram of the invention in which both injectors have a communal connection to the fuel injector triggering supply of the Electronic Control Unit (ECU) of a multi-point electronic fuel injection system.

FIG. 3 is a typical electrical circuit diagram of the invention in which alternatively separate independent triggering connections for the fuel and air injectors are provided by a customised ECU Electronic Control Unit Engine Management System.

FIG. 4 is a typical symbolic diagram of a pressurised air supply circuit required by the present invention.

FIG. 5 is a typical symbolic diagram of a pressurised fuel supply circuit required by the present invention.

FIG. 6 illustrates a typical enhanced scope of the present invention-combined Mixed Direct Injector and Spark Plug, showing a sectional view of the pressurised supplies, combination fitting and spark plug, with fuel and air injectors not sectioned.

FIG. 7 illustrates a typical further refinement of air shrouding to eliminate fuel dribble resulting from capillary action of wider angled discharge nozzle outlet apertures.

DESCRIPTION According to the present invention and referring to the drawings there is provided: 1. A Mixed Direct Injection System (see Fig. 1) comprising a fitting, 1, embodying a communal mixing passage, 2, fed by two electronically controlled solenoid operated injectors, 3 & 4, supplied by pressurised fuel supply means, 3p, (see Fig. 5), and pressurised air supply means, 4p, (see Fig. 4), respectively, the communal mixing passage, 2, having at least one stationary mixing means, 5, and a discharge nozzle, 6, having at least one outlet aperture, 7, the fitting, 1, embodying attachment means, 8, for direct connection, 9, to the combustion chamber, 10, of an internal combustion engine, 2. The primary mixing means (see Fig. 1), embodies a stationary, constrained mixing helix, 5, comprising a strip of twisted metal, 5, located inside the communal mixing passage, 2.

3. Additionally, a secondary mixing means (see Fig. 1), is embodied comprising a stationary, constrained, cone shaped propeller, 11, (located inside the discharge nozzle, 6), with slanting grooves, 12, so provided to impart high speed spiralling and further mixing before discharge out of the nozzle, 6, as an invisible combustible cloud with minimum forward velocity.

4. For economy (see Fig. 2), the solenoid electrical terminas, 3s & 4s, of each pair (in same fitting) of injectors, 3 & 4, have a communal triggering connection, 3ts, to the fuel injector triggering supply of the Electronic Control Unit (ECU), 13, of a multi point electronic fuel injection system, and preferably each air injector is enhanced by provision of a capacitor, 14, in parallel with its solenoid, 4s, and an isolating rectifier, 15, and resistor, 16, in series with the communal triggering supply, 13; the specifications of the capacitor, 14, rectifier, 15, and resistor, 16, are so provided to impart a phased delay in triggering the air injector, 4,"on"and"off'with respect to the paired electrically linked fuel injector, 3, so as to provide a cleaner shut off without fuel dribble.

5. Alternatively (See Fig. 3), the scope of the present invention includes for separate independent triggering connections, 3ts & 4ts, for said fuel and air injectors, 3 & 4, provided by a customised ECU (Electronic Control Unit) 13c.

6. The pressurised air supply means, 4p, includes (see Fig. 4), typically at least one air pressure vessel, 17, isolating on/off valve, 18, tee coupling, 19, high pressure isolating solenoid valve, 20, pressure reducing control valve, 21, with piping connection, 22, to common air pressure rail, 23, feeding said air injector, 4, said tee coupling, 19, connected via a non-return valve, 24, to an air compressor means, 25, for recharging the air pressure vessel, 17, the air compressor means, 25, being powered from an energy source means from the engine.

7. The pressurised fuel supply means, 3p, includes (see figure 5) any present day multi point fuel injection pressurised fuel supply means, including typically a fuel tank, 3ft, electric fuel pump, 3fp, fuel filter, 3ff, fuel pressure regulator, 3pr, with fuel pressure relief pipe, 3rp, return to fuel tank, 3ft.

8. An enhanced scope of the present invention includes provision for electric spark plug ignition means inside the fitting, 1, comprising (see Fig. 6) a ground electrode, 26, a high temperature resistant, high voltage insulator, 27, temperature differential air gaps, 27a & 27b, containing a spark electrode, 28, conductive glass seal, 28g, terminal stud, 28s, connection thread, 28t, and terminal nut, 28n, for electric connection to external high tension spark ignition circuitry; the ground electrode, 26, and tip of spark electrode, 28, located inside said combustion chamber, 10, in path of discharge of the nozzle, 6.

9. Preferably, the attachment means, 8 & 9, of the Combined Mixed Direct Fuel Injection System and Spark Plug for direct connection to the combustion chamber, 10, of an internal combustion engine, includes (see Figs 1 & 6), hexagon nut facets, 29, sealing washer, 30, and spark plug screw threads, 8, matching the screw threaded spark plug holes, 9, of the combustion chamber, 10.

10. As a further refinement (see Fig 7), to eliminate fuel dribble resulting from capillary action of wider angled discharge nozzle outlet apertures, 7, the fitting, 1, is provided with air shrouding means comprising typically a separate air passage, 31, with an angled constricted orifice outlet, 32, circulating high velocity pure unmixed air to a skirted cavity, 33, around the discharge nozzle outlet aperture, 7, the inlet of the separate air passage, 31, having a connection, 34, to the junction, 35, between the communal passage, 2, and discharge of air injector, 4.

Claims (10)

1. CLAIMS: 1. A Mixed Direct Fuel Injection System comprising a fitting embodying a communal mixing passage fed by two electronically controlled solenoid-operated injectors, one supplied by pressurised fuel supply means, the other supplied by pressurised air supply means, said communal mixing passage having at least one static mixing means, and a discharge nozzle, having at least one outlet aperture, said fitting embodying attachment means for direct connection to the combustion chamber of an internal combustion engine.
2. 2. A Mixed Direct Fuel Injection System as in claim 1. wherein said static mixing means includes a static, mixing helix comprising an axially twisted thin strip of metal constrained inside said communal mixing passage.
3. 3. A Mixed Direct Fuel Injection System as in claim 2. wherein additional static mixing means located inside said discharge nozzle, include a stationary, constrained, cone shaped propeller, embodying slanting grooves, so provided to impart high speed spiralling and further mixing before discharge out of said nozzle, as a combustible invisible cloud with minimum forward velocity.
4. 4. A Mixed Direct Fuel Injection System as in claims 1, 2 and 3, wherein for economy the solenoid electrical terminas of each pair (in same said fitting) of said injectors have a communal triggering connection to the fuel injector triggering supply of the Electronic Control Unit (ECU) of a multi-point electronic fuel injection system, wherein (for enhanced performance of said air injector) there is provision for a capacitor in parallel with its solenoid, and an isolating rectifier and resistor in series with said communal triggering supply (with said fuel injector), the specifications of said capacitor, rectifier and resistor so provided to impart a phased delay in triggering said air injector"on"and"off' with respect to said paired and electrically linked fuel injector, so as to provide a cleaner shut off without fuel dribble.
5. 5. A Mixed Direct Fuel Injection System as in claim 3, wherein said system alternatively includes separate independent triggering connections for said air and fuel injectors provided by a customised Electronic Control Unit.
6. 6. A Mixed Direct Fuel Injection System as in claims 1 to 5, wherein said pressurised air supply means comprises at least one air pressure vessel, isolating on/off valve, tee coupling, high pressure isolating solenoid valve, pressure reducing control valve, with piping connection to common air pressure rail, feeding said air injectors, said tee coupling connected via a non-return valve to an air compressor means, for recharging said air pressure vessel, said air compressor means being powered from an energy source means from said engine.
7. 7. A Mixed Direct Fuel Injection System as in claims 1 to 6, wherein said pressurised fuel supply means includes any present day multi-point fuel injection pressurised fuel supply means, including typically a fuel tank, electric fuel pump, fuel filter, fuel pressure regulator, with fuel pressure relief pipe return to fuel tank.
8. 8. A Mixed Direct Fuel Injection System as in claims 1 to 7, wherein said fitting includes electric spark plug ignition means comprising at least one ground electrode, a high temperature resistant, high voltage insulator, temperature differential air gaps, containing a spark electrode, conductive glass seal, terminal stud, connection thread and terminal nut for external electric external connection to high tension spark ignition circuitry means; said ground electrode and tip of said spark electrode located inside said combustion chamber in path of discharge of said nozzle.
9. 9. A Mixed Direct Fuel Injection System as in claims 1 to 8, wherein said attachment means for direct connection to said combustion chamber includes hexagon nut faceted means, spark plug screw thread attachment means and sealing washer means to match said screw threaded spark plug holes of said combustion chamber.
10. 10. A Mixed Direct Fuel Injection System as in claims 1 to 9, wherein as a further refinement to eliminate fuel dribble resulting from capillary action of wider angled discharge nozzle outlet apertures, said fitting is provided with air shrouding means comprising typically a separate air passage with an angled constricted orifice outlet circulating high velocity pure unmixed air to a skirted cavity around said discharge nozzle outlet aperture, inlet of said separate air passage having a connection to the junction between said communal passage and discharge of said air injector.